Prostheses serve to replace the function and optionally the visual appearance of a missing limb and are secured to the body of the patient. A large number of options are known for securing the prosthesis. A widespread option for securing prostheses to the extremities is that of arranging the prosthesis on a remaining part of the limb, referred to as the stump. The stump is surrounded by a prosthesis socket, which is generally dimensionally stable. An introduction opening is formed at the proximal end of the socket and at least one fastening device on which further prosthesis components can be arranged, for example joints or functional units such as prosthetic feet or prosthetic hands, is provided at the distal end of the socket. In order to achieve a good fit, a model of the stump is made and the socket is adapted to the contour of the stump model. In order to be able to compensate for fluctuations in volume, provision can be made for the socket to be manufactured in a narrower manner than the molded stump model.
In order to increase the wearing comfort, provision can be made for what is referred to as a prosthesis liner to be arranged between the prosthesis socket and the stump. The prosthesis liner generally consists of a closed main body having a proximal opening and is pulled in the manner of a sock over the stump. The elastic material adheres to the stump surface and establishes the connection between the stump and the prosthesis socket. In order to fasten the prosthesis liner to the prosthesis socket, provision can be made of mechanical locking elements at the distal end of the prosthesis liner and corresponding locking devices at the distal end of the prosthesis socket, said locking devices locking the prosthesis liner to the prosthesis socket in a form-fitting manner after fitting the stump into the prosthesis socket. An unlocking device can be used to undo the fastening of the prosthesis liner to the prosthesis socket.
A further option for fastening a prosthesis socket to a stump consists in what is referred to as suction socket liner technology, in which the prosthesis socket is sealed off with respect to the prosthesis liner in an airtight manner and the air present in the intermediate space between the prosthesis liner and the prosthesis socket is sucked or pushed out of said intermediate space. A return flow is prevented via a nonreturn valve. To this end, it is necessary to configure the prosthesis socket in an airtight manner and to ensure extensive sealing with respect to the prosthesis liner.
DE 101 53 796 A1 relates to a prosthesis socket and a prosthesis liner which has, at its distal end, a fixing member having a cylindrical peg which is provided with a rotationally symmetrical sawtooth profile. The peg is passed through an opening at the distal end of the prosthesis socket and is mechanically locked via a slide. At the distal end of the prosthesis liner, a sealing lip is arranged as a closed ring around the peg.
US 2011/0035027 A1 relates to a vacuum-assisted liner system having a flexible liner which is pulled over a stump and has at least one circumferential edge. The liner is produced from an air-impermeable material and has at least one porous region which is spaced apart from the circumferential edge, in order to allow the transport of air and moisture between an outer surface and an inner surface of the liner.
DE 101 42 491 A1 relates to a sealing arrangement for sealing off an amputation stump in a cup-shaped, airtight prosthesis socket having a tubular, elastic and airtight carrier which is able to be pulled onto the amputation stump and encloses the amputation stump on all sides in the circumferential direction. Arranged on the outer side of the carrier is a sealing lip which rests against the prosthesis socket in a sealing manner.
U.S. Pat. No. 8,052,760 B2 relates to a prosthesis liner for forming an interface between a stump and a prosthesis socket. The liner is formed in a substantially conical manner and produced from a material which is elastically deformable. The proximal end is open and the distal end is closed. At the outer circumference of the liner, separate sealing elements are fastened to the outer surface of the liner.
WO 2012/051385 A1 relates to a prosthesis liner as an interface between a stump and a prosthesis socket, in which at least one resilient sealing element extends radially outward and at least along a part of the circumference of the liner. A cushion for controlling the volume is arranged in the liner and pushes the sealing element outward.
US 2012/0191217 A1 relates to a socket system having a vacuum liner for prosthetic or orthotic devices. A region made of an elastic material is arranged on the closed liner at the distal end, said elastic material being harder than the material of the rest of the liner. The region has a concave section which extends inward from an outer end surface of the region. The distal region and the concave section form at least a part of a vacuum pump in order to pump air out of the intermediate space between the liner and the prosthesis socket.